class MyContextMenuStrip : ContextMenuStrip
{
    private C1Editor _owner;
    private ToolStripMenuItem _btnCut, _btnCopy, _btnPaste;
            
    public MyContextMenuStrip(C1Editor editor)
    {
        // save reference to parent control
        _owner = editor;
            
        // create menu items
        _btnCut = (ToolStripMenuItem)Items.Add("Cut");
        _btnCut.ShortcutKeys = Keys.Control | Keys.X;
        _btnCopy = (ToolStripMenuItem)Items.Add("Copy");
        _btnCopy.ShortcutKeys = Keys.Control | Keys.C;
        _btnPaste = (ToolStripMenuItem)Items.Add("Paste");
        _btnPaste.ShortcutKeys = Keys.Control | Keys.V;
    }
            
    protected override void OnItemClicked(ToolStripItemClickedEventArgs e)
    {
        // close menu (not automatic)
        Close();
            
        if (e.ClickedItem == _btnCopy)
            _owner.Copy();
        else if (e.ClickedItem == _btnCut)
            _owner.Cut();
        else if (e.ClickedItem == _btnPaste)
            _owner.Paste();
        // on to base class
        base.OnItemClicked(e);
    }
            
    protected override void OnOpening(System.ComponentModel.CancelEventArgs e)
    {
        if (_owner.Mode == EditorMode.Preview)
        {
            e.Cancel = true;
        }
        else if (_owner.Mode == EditorMode.Source)
        {
           _btnCopy.Enabled = _owner.CanCopy;
           _btnCut.Enabled = _owner.CanCut;
           _btnPaste.Enabled = _owner.CanPaste || _owner.CanPasteAsText;
            
        // on to base class
        base.OnOpening(e);
        }
   }